1. Field of the Invention
This invention relates to the stabilization of solutions of poly(dichlorophosphazene) through the use of complexes with which water will preferentially react rather than the phosphorus-chloride bonds which are present in the poly(dichlorophosphazene) polymers.
2. Prior Art
Poly(dichlorophosphazene) is commonly dissolved in organic aprotic solvents such as benzene, toluene, chlorobenzene, tetrahydrofuran, 1,2-dimethoxy-ethane or cyclohexane. It is of great importance that the solvent which is used be free of water since water readily reacts with the reactive phosphorus-chloride bonds in the polymer backbone. The reaction of water with these bonds eventually leads to cross-linking and gelation of the poly(dichlorophosphazene) in solution. The cross-linked polymer is unsuitable for preparation of any stable derivatives of poly(dichlorophosphazene), thus the protection against cross-linking or gelation is necessary for any overall derivatization production scheme for substitution of poly(dichlorophosphazene).
H. R. Allcock et al., Journal of Inorganic Chemistry, Vol. 5, 1966, on page 1714, discloses that SnCl.sub.4 can be added to poly(dichlorophosphazene) to inhibit the cross-linking process, however, this stabilization method has proven to be unsatisfactory for prolonged storage.